RE: [RFC v2] /dev/iommu uAPI proposal

[Tian, Kevin]

> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Wednesday, July 14, 2021 7:03 AM
> 
> On Tue, Jul 13, 2021 at 10:48:38PM +0000, Tian, Kevin wrote:
> 
> > We can still bind to the parent with cookie, but with
> > iommu_register_ sw_device() IOMMU fd knows that this binding doesn't
> > need to establish any security context via IOMMU API.
> 
> AFAIK there is no reason to involve the parent PCI or other device in
> SW mode. The iommufd doesn't need to be aware of anything there.
> 

Yes. but does it makes sense to have an unified model in IOMMU fd
which always have a [struct device, cookie] with flags to indicate whether 
the binding/attaching should be specially handled for sw mdev? Or
are you suggesting that lacking of struct device is actually the indicator
for such trick?

Thanks
Kevin